Two-cycle internal-combustion engine.



L, ATWOOD.

TWO-CYGLB-INTERNAL COMBUSTION ENGINE.

MPLIGATION FILED Nov. 2s, 1912.

2 SHEETS-SHEET'L L. ATWOOD.

TWO-CYCLE INTERNAL OOMBUSTION ENGINE.

APPLICATION FILED NOV. 26, 1912.

Patented Mar. 2, 19K).

2 SHEETS-SHEET 2.

@M4 @w v, 3 @m1 fTED STA'ijlTENT FFQE.

LEONARD ATWOOD, OF FARMINGTON, 'MAINE ASSIGNOR 0F ONE-HALF TO A. H. GILLARD', OF ENGLEWOOD, NEW JERSEY.

TWO-CYCLE INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent.

Patented Mar. 2, 1915.

Application led November y26, 1912. Serial No. 733,589.

To all whom it may concern: i

Be it known that I, LEONARD A'rwoon',

a citizen of the United States of America,

and a resident of Farmington, county of Franklin, and State of Maine, have inventedf certain new and useful Improvements in Two-Cycle Internal-Combustion Engines, of which the following is a specification.

This invention has reference to improvements in internal combustion engines in 'which the pressure for driving the, piston is obtained by igniting an explosive mixture of air and combustible fuel in the cylinder 'of the engine. y

The invention pertains particularly to Atwo-cycle engines which have only two phases or strokes in a complete cycle and 'has for its special purpose to avoid certain inherent defects of two-cycle internal combustion engines. By virtue of its construction the novel two-cycle engines are adapted to take the place of four-cycle engines and thus are not limited as to size and application. This hasbeen primarily attained by a novel arrangement of valves Iby means of which the engine receives its charge on the upward stroke of the piston after the exhaust ports have been closed whereby the one defect of having the exhaust ports and inlet ports for the combustible fuel open at the same time is fully avoided. Likewise back fires cannot take place, the exhaust ports being open and the intake valve closed 'at the time when back fires might occur and the exploded gases, being under great pressure, force back the piston whereby the exhaust ports are gradually opened at a time when the inherent pressure of the exhaust gases is still so great as to force them through the exhaust ports and create an impetus -of the moving gases to such an eX- tent that a rerefied space is formed within the cylinder. Accordingly, compression of part o the exhaust gases can not take place. The novel two-cycle engine is provided with an intake valve which is regulated. The piston consists of a full size portion fitting closely the inner walls of theylinder. This portion compresses the charge to be exploded on theupward, outward or compression stroke. A reduced ynarrow piston portion permits of compressing the charge which lhas just entered on vthe Vdownward, inner or power stroke. In this'manend of the cylinder.

ner a compound compression is effected. The, compressed fresh charge is forced through a series of lengthwise arranged to an intake valve on the outer or explosion This Valve is automatically opened and closed and the fresh charge issuing into the explosion zone of the cylinder is then compressed and ignited. Graduated exhaust ports are helically arranged through which the exhaust gases are gradually expelled. The section of lthe crank circle in which the crank is located when the burned charge is expelled is the lower section of the same; the next following section is the one during which the exhaust 'ports are closed and then a new charge admitted, thus obviating the loss of fuel 'which would go'out with theexhaust gases and the' latter portion of which would tend to ignite the incoming charge' by premature ignition caused by its inherent heat. This might tend to involuntarily reversethe motion of the engine. As the cylinder becomes hot during use the fresh charge is subject' to an auxiliary heating .while being compressed, by virtue of the reduced portion of the cylinder', during the downward or power stroke. This aids in forcing the fresh charge through the lengthwise arranged ports into the tube or channel and intake valve through openings into a tube or channel which leads which said fresh charge enters the explosion i' zone of the cylinder.

.In order to render the invention entirely lclear reference is had to the accompanying drawing showing a vertical engine as an example, and in which:

Figure l represents in vertical sectional elevation partly broken away a novel twocycle engine which embodies in desirable form the present improvements and showing the piston as performing the compression stroke. Fig. 2 is a similar view showing the piston as performing the power stroke. Fig. 3 illustrates in rear elevation the two-cycle engine with mechanism for permitting the engine to run in one direction, reverslng same and placing 1t `1n a t kneutral position. Fig. 4 is a partial section I.

on line 4 4 of Fig. 3. Fig. 5 is a -vpartial section on line 5--5 of Fig. 3. Fig. 6 is a horizontal section on line 6-6 of Fig. 3. Fig. 7 represents in plan view' Vvalve tripping mechanism for opening' and closing the inlet valve of the explosivef'zoii'e. Fig.

8 is a horizontal section on line 8--8 of Fig. 1. l

Similar characters of reference denote like parts in all the figures.'

In the drawing 1 represents the cylinder which is closed at the top and-2 is the crank case or splashcase. The piston consists of a full size `portion 3 which fits the inner walls of the cylinder closely and al reduced portion 7 that passes through the upper portion of the splash case as shown in Figs.

1 and 2. The connecting rod 9 is pivoted to l The charge entering thecylinder through the inlet pipe 11 is somewhat compressed during Athe downward or power stroke of the piston. The charge is then forced through a seriesv of lengthwise arranged and graduated ports. 14 into a tube 15 shown in Figs. 3 and 4. This passage may also consist of a channel cast directly with the cylinder. The tube or channel 15 extends up to the end of the cylinder and connects with an inlet port 16 through which the somewhat compressed charge enters the explosionzone of the cylinder. The inlet port 16 is normally closed by an induction valve 17 which is normally pressed down by the spring 18 as shown in Fig. 4. A rod 19 is connected with the induction valve 17- and extends through the tube or channel 15 in a downward direction. A guiding support'20 retains the rod'19 `inthe desired location. The bottom portion 21 of this rod is enlarged and rests on the inner end portion of a pivotallv secured lever 22, see Fig. 3. The downward movement of this lever is limited by' a small support 23. The lever 2,2 is actuated by valve tripping mechanism shown in detail in Fig. 3. This mechanism cmprises a pivoted lever 24 having a curved portion 25. movement of this lever in a downward direction. Below the curved portion 25 of the lever 24 a circular valve tri ping member 26 is mounted on the shaft 2 of the crank mechanism, and thus operated thereby. The circular member 26 is provided with means for raising the lever 22 once during each revolution. The lever 22 in turn raises the rod 19 and with it the, induction valve 17 which thus connects the channel 15 with the inlet port 16 and permits of the entrance of a -fuel charge into the explosion zone of1 the A short stop 241. limits the cylinder. The force of the spring 18 is thus overcome but on the further rotation of the circular member 26 the spring becomes active and closes off the inlet port 16. It is evident that the piston then is in its lowest position and has performed the downward or power stroke as shown in Figs. 1 and 4.

As far as described the crank mechanism and accordingly the machine is moved in but one direction, say in the direction indicated by the arrows in Figs. 1 and 2. In order to render it possible to reverse the engine, mechanism is provided in connection with the valve tripping device which not only permits of running the engine in either direction but also is adapted to place the valve tripping mechanism in a neutral position so that'the engine runs dead for instance when an automobile is going down hill. This mechanism consists of a lever f28 which is pivoted to the lever 24, see Figs. 1, 2 and 3. The lever 28 is rigidly connected to a lever .29 provided with a little knob 30 and a handle l31. On the adjoining portion of the cyllnder there are indentations 32 which are adapted to receive the knob 30. 'lhree of these indentations are shown in Figs. 1 and 3. For the purpose of making this mecha.

nism operative the curved part 25l of the lever 24 is cut out so that one protruding portion 33 is formed on the rightportion and the second protruding portion 34 on its left portion. To actuate these'protruding portions 33 and 34 the circular valve tripping member 26 has on its right portion a protruding knob 35 adapted to engage said upper portion 33 and a protruding knob 36 l on its left portion adapted to engage saidl leftprotruding portion 34, see Figs. 3 and 7. Assumingl now that the knob 30 of the lever 29 is placed in the middle indentation 32 then the protruding knobs 35, 36 pass the curved portion 25 of the lever 24`without raising it. This mechanism is then inthe neutral position and the machine runs dead no matter in whatdirection it is running. The lever 28 is then in'a vertical line as shown in full lines in Fig. 3.- When the lever 29 is moved so that the knob 30 is in the lower indentation 32 then the crank moves in the direction indicated by the arrows in Figs. 1 and 2 and the right protruding knob 35 of the valve tripping member 26 raises the curved portion 25 of the lever 24 and thereby opens the valve 16. yUpon further rotations of the member 26 the spring 18 closes the valve 16. If now the lever 29 is moved so that the Vknob 30 is raised into the upper indentation 32 the left protruding knob. 36 of the valve tripping member 26 raises said curved member and opens' the valve 16 while the right knob 35 remains inactive.` Thus the machine is reversed by the lateral dislocationof 'the curved member 25. y

3. When the engine is reversed said curved portion 25 is in the position shown in dotted lines to the left in Fig. 3. In the engine.

two latter instances the tripping means open the inlet valve 16 to its fullest extent. If the operator desires to permit more or less combustible fuel to enter the explosion zone of the cylinder the knob 30 is placed in any desirable position between the central indentation 32 and the outer ones whereby the valve tripping means are raised not quite so high andthe inlet port 16 is opened `to a smaller extent. In this way said inlet port 16 allowing the fuel to issue into the explosion zone of the cylinder may be regulated to any desired degree. It is evident that more than three indentations 32 may be provided. Ifthe knob 30 is between two indentations it is held in position by frictional contact.

As shown in the first four figures the inlet port 16 is located somewhat below the upper end of the cylinder and as the spring 18 closes said inlet port 16 upon further rotation of the circular valve tripping member 26 this'port is closed before ignition by the spark plug takes place and therefore back fires cannot occur back of the inlet valve.

It is evident from the above that the fuel charge in the explosion zone is compressed when the piston moves upward or performs the compression stroke. Upon the 'downward movement of the piston the initial charge having meanwhile entered through the inlet port 11 at the lower end of the cylinder is somewhat compressed and forced throughy the graduated ports l14 into the. channel 15. Thus a compound compressiontakes place in this novel two-cycle charge is further increased by the heat radiated from the cylinder so that a quick and reliable issue into the explosion zone is effected. When the piston has reached its uppermost location indicated by the line 37 in Figs. 1 and 2 ignition takes place, and the expanded gases force the pistondownward which then performs the power stroke as indicated by the arrow in Fig. 2. When the upper end portion of the piston reaches the graduted exhaust ports 38 the exhaust gases are gradually expelled through said ports because the same are helically arranged on the cylinder as shown in detail in Fig. 5. When the upper end' of the piston 3 reaches the exhaust zone and opens the ports 38 the lower end of the piston 3 commences to close the lengthwise arranged The pressure of the initial fuel graduated ports 14 andwhen the upper portionof the piston 3 has passed the exhaust zone all said ports 14 are closed as indivsated in Fig. 1. In this way the graduated exhaust ports 38 are successively opened,

the smallest being opened first, and successively closed, the largest being closed rst, which -is a great advantage. After the fresh fuel charge has passed through the channel 15 and the valve 16 it enters into the cylinder. The piston 3 commences now the compression stroke by moving upward creating an attenuation in the space 13 whereby a fresh charge enters through the inlet pipe 11 and check valve 12. When the piston has passed the graduated ports 14, the same are open allowing the fresh charge to enter-the channel 15 where immediately before no pressure existed. When the piston 3 reaches its uppermost position again ignition takes place as before and the cycle of operations is repeated. In this way fresh fuel is taken in while the piston performs its upward or compression stroke.

. For the purpose of cooling the cylinder, ribs 39 are cast thereon annularly arranged. The ribs are longitudinally pierced and form vopenings 40. The perimeter of the ribs is cut out to form spaces 41, see Fig. 6. The ribs 39 are surrounded by a jacket 42 having openings 43 for the entrance of cooling air. The cooling air is drawn through the ribs in a novel manner as shown in Fig. 3. An exhaust tube 44 through which the exhaust gases are expelled com- 100 municates with a pipe arrangement 45, 46 which pass into the exhaust tube and is united there to form a common issue opening as shown in Fig.3. Thepipes 45, 46

connect with the interior space of the ribs 105 and are secured on the jacket l42. Assuming now that exhaust gases -are passing through the exhaust tube 44.the'n a draft is created and the air in the pipes 45, 46 and in the space between the ribs is drawn out 110 by the draft of the passing exhaust gases. 'In the same proportion in which the air is drawn out fresh air passes through the `jacket openings 43 into the ribbed portion of the cylinder and cools the said cylinder. 115

It is easily understood that the quantity of cooling air drawn through the cylinder ribs is proportionate to the quantity and speed of the exhaust gases that are expelled.

As shown in Fig. 3 the pipes 45, 46 are 125 connected to the cylinder jacket and somewhat away from the same. The exhaust pipe 44 is much wider than the issue opening of the pipes 45, 46. Accordingly, there is a space in .said pipey 44 through which 130 Thus the cooling of the cylinder takes place 129 phase fresh air enters through the pipe 44 and ports 38 which air forms part of the next explosive mixture,

For the purpose of avoiding cranking of an automobile orv vehicle a device is pro-l vided for deliveringvan initial charge into v the explosion zone for starting the engine.

This device consists of a pipe 47 with check valve 48 connecting the lower portion of the cylinder, where theI initial charge is conipressed during the power stroke of the piston, with the combustible fuel tank from which a second pipe 49 leads to the explosion zone of the cylinder. This pipe is provided with a handvvalve 50 near the cylinder which may be operated at will for the purpose of allowing gasolene vapors to enter the explosion zone.' always under pressure becausel the piston during the power stroke forces vapors through the pipe 47 into the combustible fuel tank and the quantity of pressure is regulated by the check valve 48 provided in said pipe 47.

I claimas my invention:

l. An internal combustion engine of the. two-cycle type comprising, a cylinder with piston, a fuel inlet port to a compression compartment within said cylinder, said port being near the inner end of the cylinder and active during the compression stroke of the piston, lengthwise arranged graduated ports in the cylinder near the inlet port, a channel on the cylinder in connection with said ports, an adjustable induction valve at the end of said channel, and an inlet port in the explosion zone of the cylinder, said fuel charge being compressed during the power stroke of the piston and heated by the hot surfaces of the cylinder and piston.

2. An internal combustion engine of the two-cycle type comprising, a cylinder with piston, and an inlet port to a compression .compartment within said cylinder, said port being located near the inner end of the cyl'- inder and active during the compression stroke, lengthwise arranged graduated ports for connecting with the explosion zone near said inlet port and active during the power stroke, and graduated exhaust ports arranged annularly and helically in the center portion of the cylinder and adapted to Such vapors are?.

be opened toward the end of the power stroke while closing the graduated inlet ports. Y

3. An internal combustion engine comprising a cylinder and a piston therein, the cylinder being *provided with a' series of over-run, helically-arranged exhaust ports, of Varying size.

4. An internal combustion engine` comprising a cylinder, a piston therein, exhaust means comprising a series of over-run helically arranged exhaust ports of gradually increasing, size towardthe inner end of the cylinder.

5.'An internal combustion engine of the two cycle type, comprising a cylinder having a piston therein dividing said cylinder into a combustion compartment' and compression compartment; a valved fuel inlet passI for connecting said compression and combustion compartments, a valve in said by pass for introducing the fuel charge into the combustion chamber, at a point near the outer end thereof; exhaust means for the combustion compartment comprising a series of helically arranged ports of gradually increasing size toward the inner end of the cylinder located near the end of thel power stroke, said valve for introducing the gases into the combustion compartment being operable after the closing of said exhaust means. n

6. An internal combustion engine of the two cycle type comprising a cylinder; a piston therein, dividing sa1d cylinder into a compression compartment and a combustion compartment; a valvedfuel inlet to said compression compartment; a by-pass from said compression compartment to said combustion compartment, a series of ports decreasing in size toward the inner end of the cylinder, between said compression compartment and' said by pass, said ports being over-run by' said piston, a spring-closed slide valve in said by-pass, a crank shaft for said engine, and a cam carried thereuponya -rod receiving an impulse from said cam on the crank shaft of the engine, for o ening'said slide-valve, after the closing o? the exhaust ports ofthe combustion compartment. f n

Signed at. New York, N. Y., thls 23rd day of November, 1912.

LEONARD Afrwoon. 

